This project focuses on the development of single- and multi-photon sources for quantum information applications based on photonic crystal fibres (PCFs). It brings together two internationally renowned UK research teams in order to design, build and test devices which are optimally tailored to this application.Recent developments in quantum optics have shed new light on the way we see information, communication and computation. No-longer are we limited to classical operations, but we can also harness the fundamental quantum nature of light to real-world uses. The most developed example of this is quantum cryptography; a way of exchanging cryptographic keys with provable security. Various groups, including ours, are now looking to go beyond quantum cryptography to perform multi-photon quantum logic and quantum communication experiments. Key resources for these experiments are sources of heralded single photons, pair photons and entangled pair photons and eventually multiple photons. There is currently a drive towards experiments in optical fibre, because of the inherent single spatial mode, ease of alignment and long transmission lengths possible for communication and teleportation experiments. Recently through discussions between the Bath and Bristol groups we realised that PCFs could be used as efficient single mode pair photon sources. Our combined knowledge of PCFs and the quantum information 'toolbox' has then led to the development of this proposal. We have already performed ground breaking preliminary experiments generating pair photons using off-the-shelf fibre originally designed for other applications. Here we are interested in engineering the ultimate performance from fibre sources of photon pairs and hope to produce the worlds first three photon source. This will allow us to perform world leading multiphoton experiments with quantum information applications in mind.